Method of and apparatus for preventing knocking in internal-combustion engines



F. A.- HOWARD ET AL ING METHOD OF AND APPARATUS FOR PREVENTING KNOCK IN INTERNAL COMBUSTION ENGINES Filed Jan. '7. 1922 Patented duly 10, 1928a A UHTD stares FATNT FFECO FRANK A. HOWARD, OF ELIZABETH, AND THOMAS E. PARKER, OF JERSEY CITY, NEW JERSEY, ASSIGNORS T0 STANDARD DEVELOPMENT COMPANY, A CORPORATION OF DELAWARE.

METHOD OF AND APPARATUS FOR PREVENTING KNOCKING IN INTERNAL-COMBUSTION ENGINES.

Application filed January 7, 1922. Serial no. 527,665.

This invention relates to a method of and apparatus for preventing knocking in variable load internal combustion engine and is particularly adapted to be used on small stationary engines and agricultural tractor engines, but is adapted for use with automotive internal combustion engines generally.

An object of this invention is to provide a method of and apparatus for preventing detonation or knocking in an internal combustion engine which occurs particularly with the common motor fuels such as gasoline and kerosene when the compression pressure exceeds a certain amount depending on the kind of fuel and on the design and condition of the engine cylinders.

This and other objects are accomplished by this invention which consists primarily in feeding a low compression fuel to the engine through a jet and feeding a high compression fuel to the engine through a secondary jet the secondary jet becoming operative as the engine throttle is opened a predetermined amount.

Referring now to the accompanying drawings, Figure l is a vertical section through a carbureter embodying the invention and Fig; 2 is a partial front elevation of the same showing the operating mechanism.

The carbureter comprises a mixing tube 10 to which one or more jets 11 supply a low compression fuel A such as gasoline or kerosene, said jets being in communication with a well known type of fuel cha znber 12.

The posterior throttle 13 is placed in the mixing passage 10 and secured to the shaft 14 which is journalled in the sides of the passage, one end of the shaft extending throu h and having a lever 15 secured thereon; i throttle control rod 16 is. hingedly secured thereto for controlling the throttle in a well known manner either by means of a hand throttle lever or a foot accelerator.

An auxiliary passage 17 connects with the main passage 10 between the jets 11 and the throttle 13. A jet 18 communicates with the auxiliary passage 17 and is supplied with a high compression fuel Bthrough the float chamber 19. Thisfuel B may be ethyl alcohol or it may be one of the well known fuels containing aniline or iodine in sufficient quantities to prevent the fuel from knocking except at relatively high compression pressure.

A restriction 20 is placed anterior to the throttle 13 in the passage 17. The butterfly valve 21 normally closes communication between the auxiliary passage 17 and the main mixing passage 10. This valve is keyed on a shaft 22 which is journalled in the sides of the passage 17. One end of this shaft extends through the side of the passage and has an operating arm 23 secured thereon as shown in Figure 2. This arm is normally held against a stop 21L by the spring 25. An extension 15 of the lever 15 has an end 15 which may be moved into contact with a pin 26 on the outer end of the arm 23 as the rod 15 is moved to open the throttle 13. As the end 15 strikes the Pin 26 it moves the arm 23, thereby opening the valve 21. The lever 15 can then be moved until the dotted line position shown in Figure 2 is reached at which time the lever 23 is stopped by'the pin 27.

. The method of operation of this carbureter is as follows:

The parts shown in Figure 1 and in full lines in Figure ,2 are in position for idling, at which time the valve 21 is closed and the throttle 13 is nearly closed. Durin idling all of the intake air passes through t e main mixing passage 10 and receives only low compression fuel A through the jets 11.

As the throttle 13 is opened the engine will receive a denser charge of the combustible mixture. Before the density of this mixture becomes great enough to produce knocking the end lever 15 strikes the pin 26, opening the valve .21, and admitting the high compression mixture through the auxiliary passage 17. It might happen, however, in some cases as at very low speed and heavy load, that the density might become so great as to produce knocking before the end of the lever 15 strikes the pin 26. In that case the operator has only to open the throttle 13 further, thereby admitting the high compression mixture. It will be obvious that as the throttle 21 is opened the portion thereof above the pivot will swing into the path of fuel from jets 11, thus obstructing the flow of air from the main intake which obstruction will be substantial when the throttle 21 is fully open. With maximum load upon the engine there Will be fed a larger proportion of high compression fuel than Would claims, in Which it is our-intention to claim otherwise result from the relative cross sectional area of the intakes.

It will thus be seen that the engine may use a higher compression ratio with a con-i sequent inorease in efficiency. The average small stationaryengine and many tractor and boat engines use full compression only a very small percentage of the time and When they do. knocking is prevented by the automatic introduction of the necessary proportion of high compression mixture.

While we have shown and described a single embodiment of our invention, it is to be understood that. it is capable of many modifications. Changes, therefore in the construction and arrangement may be made Without departing from the spirit and scope of the invention as disclosed in the appended amas? ondary passage supplied from a'source of high compression fuel and means operably connecting said valve and throttle so that said valve begins to open when the throttle is opened a predetermined amount.

2. A carburetor for an internal combustion engine'having a mixing passage, a low compression fuel jet delivering thereto, a throttle in said passage, a secondary passage leading to said mixing passage, a valve in said secondary passage, a jet in said secondary passage supplied from a source of knock preventing fluid and means operably connecting said valve and throttle so that said valve begins to open when thethrottle is opened a predetermined amount.

3. Means for feeding fuel to an internal combustion engine comprising, in combination, a plurality of intake passages one of said passages opening into another thereof, a fuel jet in each passage, separate float chambers supplyingeach jet, a throttle control for the juncture of said passages, a common throttle controlling the flow of air through all of said passages, manual control means for said common throttle and a lost motion connection for initiating opening movement of said first named throttle after initial opening of said common throttle.

FRANK A. HOWARD. THOMAS R. PARKER. 

